#include <iostream>
using std::cout;
using std::endl;

//仅仅只是声明
namespace wd{
void display();
void show();
}

namespace wh{
void print(){
    cout << "wh::print()" << endl;
}

void show(){
    cout << "wh::show()" << endl;
    wd::display();

}

}//end of namespace wh 


namespace wd{
void display(){
    cout << "wd::display()" << endl;
    wh::print();
}

void show(){
    cout << "wd::show()" << endl;
    wh::show();
}


}//end of namespace wd 

//作用域限定符
void test(){
    wd::show();
}

void test2(){
    using namespace wd;
    show();
}

void test3(){
    using wd::show;
    show();
}

int main()
{
    test3();
    return 0;
}

